Dual elevation weapon station and method of use

ABSTRACT

A gimbaled weapon system (GWS) includes methods for bore sighting a weapon mounted to the GWS. The GWS includes a sensor aligned with the bore of the weapon which generates an image of a target. The target image generated by the sensor is compared with a target image or reticle produced by the sighting system. The target image or reticle of the sighting system is moved or adjusted using operator controls until it is in alignment with the target image produced by the bore-aligned sensor. The procedure can be conducted at different ranges to targets.

RELATED APPLICATIONS

This is a continuation in part of prior application Ser. No. 10/304,230filed Nov. 26, 2002, the entire contents of which is incorporated byreference herein, for which priority benefit under 35 U.S.C. section 120is claimed.

BACKGROUND OF THE INVENTION

1. Field of Invention

My invention relates generally to gimbaled weapon stations (GWS) thatprovide sighting, fire control and a weapon cradle in a self-containedsystem and to methods for using a GWS. In particular, the gimbaledweapon station of my invention allows a weapon cradle and a sightingsystem to move together in azimuth, but each can be elevated completelyindependently of each other. This allows for continuous target trackingand sighting regardless of the super-elevation needed for the weapon toachieve the correct ballistic trajectory. My weapon station can also bestabilized and operated remotely.

2. Description of the Prior Art

Target tracking and weapon control systems are known. For example, onships, a single weapon sight that can move in both azimuth and elevationcan control and direct fire of several large weapons. These largeweapons can also move in both azimuth and elevation in response tosignals received from a fire control computer, which receives input fromthe separately controlled weapon sight. For smaller weapons, such asmachine guns, it is known to combine the weapon sight and cradle on asingle platform typically with the sight mounted directly on the weaponor the weapon cradle, but in either case there is only a singleelevation axis. One such small weapon control system is disclosed inU.S. Pat. No. 5,949,015, which provides for a weapon mount and sightingsystem on a single gimbaled mount. The system can be operated by remotecontrol and includes gyro stabilization. Such systems, however, sufferfrom the drawback that both the gun sight and the weapon share a commonelevation mechanism. In other words, as the operator moves the gun sightto track a target in either azimuth or elevation the weapon mustnecessarily follow. Accordingly, if the operator raises the gun sight inelevation to track the target the weapon will also raise in elevationbecause there is only a single elevation mechanism to raise both thesight and the weapon. In these prior art systems, it is typical that thegun point and the aiming system (gun sight combined with basic firecontrol) are directed at the same target coordinates. Various sensorsare typically used for the aiming systems; for example, visible andinfrared imaging devices to view the target and a laser range finder todetermine distance to the target. However, in situations referred to assuper-elevation, where the weapon must be elevated to a greater anglethan the target line of sight in order to launch the projectile to thehit the target over a long distance, the sighting or aiming system nolonger views the target since the aim point of the gun no longerincludes the target in the field of view.

In situations where a fire control computer can correct for ballistictrajectory (i.e., it can automatically raise the weapon to asuper-elevation position to ensure the projectile impacts the target) aserious problem arises when there is only one elevation axis. When thefire control computer super-elevates the weapon, the sight must alsoincrease in equal elevation. This causes the user to completely loseview of the target in the sight. If the user tries to override the firecontrol computer and lower the sight to regain view of the target theweapon will also be lowered causing a fired projectile to fall short ofthe designated target.

The art has recognized this serious problem and has attempted to providea solution. For example, some weapon systems provide an offsetmechanism. One such mechanism counter rotates the gun sight from the gunby an amount needed to bring the target back into the field of view ofthe sight. The disadvantage of this system is that it can introduceerrors in the aiming accuracy because of the added complexity and massof the additional counter rotation system components, which are placedon the single weapon elevation axis. This added complexity and mass mustbe added to the sole elevation mechanism, which greatly increases thechances for error in aiming the gun during super elevation. Anotherdisadvantage is that counter rotation has a very limited range ofmovement and it can also introduce target image blur as the offsetbetween the gun and sight is being established. Prior art systems canhave offset mechanisms that cause either small mechanical elevationchanges of the gun, the sight, or cause an electronic repositioning ofthe sight reticle in the sight display. U.S. Pat. Nos. 5,456,157,5,171,933, and 4,760,770 each disclose variations in the type of offsetmechanism utilized by the weapon system. For example, in the '933 patentthe gun is offset by several servo motors to achieve super-elevationonce target acquisition is acquired by the user. In the '157 patent acomputer generated offset of the sight reticle is used to correct thegun aim point for super-elevation targeting requirements. In each ofthese known offset systems, however, the amount of offset possible isvery limited, which of course drastically limits target rangecapability. A need therefore exists to provide a gimbaled weapon system(GWS) that avoids these problems and that allows mechanical elevation ofthe sighting system independent of weapon elevation, while allowing theweapon to achieve a super-elevation position to ensure target hitaccuracy.

Accordingly, one object of my invention is to provide a self containedGWS that has two separate elevation means, one for a sighting system andone for a weapon cradle, where the cradle can hold a variety ofdifferent weapons. This system provides for totally independentelevation axes and associated control and drive mechanisms.

Another object of my invention is to provide a GWS that eliminates theneed for an offset mechanism when super-elevation is needed for correctballistic trajectory. This is accomplished by providing full elevationaxes for both the weapon cradle and sighting system.

A further object is to provide a GWS where the dual elevation axes arestabilized independently or in common. Stabilization is very beneficialwhen large mass weapons are used with my GWS or when the GWS is used ona moving platform, such as a tank, troop carrier or other wheeledvehicle or boat deck.

Yet another object of my invention is to provide a control algorithm tocoordinate the movement of the two independent elevation axes so thatthe user can continuously view and track a target without interruptionand which will allow the weapon cradle (and the installed weapon) toachieve a correct super-elevation position independent of the actualelevation of the sighting system.

Other objects will be recognized upon reading the following disclosurein conjunction with the accompanying figures.

SUMMARY OF THE INVENTION

My invention is directed to a gimbaled weapon system (GWS) that combinesa weapon cradle and a sighting system in a self-contained unit that iscapable of 360° rotation in azimuth. The sighting system of my inventionincludes the actual sighting device or mechanism itself, including theassociated optics and electronics, and also may include a line of sight(LOS) reflector that transmits or reflects images to the sightingdevice. My GWS is capable of either manual or remote control operationand also provides independent elevation axes for both the weapon cradleand the sighting system. Separate elevation axes allow the weaponoperator to always maintain visual contact with the target through thesighting device even during a super-elevated condition of the weapon.Coordination between the two separate elevation axes is accomplishedusing a control unit containing one or more software algorithms thatanalyzes and controls the relative position of each elevation axis basedon inputs received from GWS subsystems including position sensors oneach axis, fire control processor, operator display commands, sightingsystem, stabilization system or from other systems, such as a hostvehicle. The fire control processor monitors and processes range data,platform cant, ammunition and weapon type, ambient pressure andtemperature, and bore sight information. The sighting system provides animage of the target using visible and or infrared video cameras andrange data through the operation of an active device, such as a laserrange finder or through the use of a passive device. Preferably thelaser range finder is optional eye safe Class 1, which provides rangemeasurement accurate to +/−10 meters for engagement of vehicle sizedland, maritime and aerial targets at ranges up to 5000 meters. My GWScan also provide the capability for the weapon operator to zero theinstalled weapon at selected ranges. Zeroing consists of adjusting thebore-sighted reticle position (aim point) based on the results of weaponfiring. Zeroing controls provide for reticle movement in increments ofless than 0.1 mil in azimuth and elevation. Bore sighting in myinvention can be accomplished without exposing the operator to theoutside environment, and more importantly to hostile fire, by the use ofa remote sensor that is aligned with the bore of the particular weaponmount on the GWS. This remote sensor transmits a target image to theoperator for comparison with the target image captured by the sightingsystem. The sighting system is electronically adjusted, typically byelectronic manipulation of the target reticle, so that the two targetimages coincide.

The GWS includes a smart system that can sense the specific type ofweapon installed in the cradle. This information, along with theidentification of ammunition type, and other data that can be enteredthrough the use of a touch screen video display physically located awayfrom the GWS, is sent to the fire control processor. Of course,depending on the weapon mounted the ammunition will automatically beknown and selected by the smart system. For those weapons that arecapable of firing different ammunition, then input of ammunition type isnecessary. The fire control processor provides for accurate fire controlof the weapon by using the information obtained from the smart system,range-to-target data, line of sight (LOS) indication, cant of the GWSplatform, and ambient temperature and pressure, to calculate a firecontrol solution. In addition to providing super-elevation and azimuthdisplacement (projectile drift) signals, the fire control solution isused to re-orient the weapon and sight reticle in azimuth while allowingthe operator to maintain visual contact with the target in a highmagnification-viewing field. However, in another mode of operation wherethe sighting system has independent elevation, the weapon is elevatedand moved in azimuth to compensate for projectile drift and to developtarget lead. Target lead is used to compensate for the relative motionbetween the target and weapon aimpoint. To keep the aimpoint on thetarget, the fire control solution is calculated using the tracking ratesfor azimuth and elevation that are generated by the gimbal. Thecommanded tracking rates come from the joystick or from a video-trackingdevice. Once the weapon and sight are moved in azimuth, the laser rangefinder is no longer pointed at the target preventing additional firecontrol solutions from being calculated. This condition is corrected byproviding a small dynamic (+/−10 degree) azimuth adjustment to thesight. This small azimuth adjustment or correction is in the oppositedirection of the target lead direction and can be accomplished using asecond separate azimuth drive means that rotates just the sightingsystem +/−10 degrees. Alternatively, and more preferably, this secondazimuth drive means moves an LOS reflector as opposed to the sightingdevice itself, because the LOS reflector is much less massive ascompared to the sighting device. Because the second azimuth drive meansis associated only with the sighting system it does not rotate or movethe weapon cradle. The weapon aimpoint can then lead the target and thesight can still accurately point the laser ranger finder.

My invention can also be transformed from a remotely operated GWS to amanually operated system in the event platform system power is lost.Manual operation allows the weapon operator to traverse the GWS inazimuth, elevate the weapon mount, charge ammunition and fire theweapon. The GWS of my invention can be used on all forms of movingground vehicles, helicopters, ships, boats and planes, and can accept avariety of weapons, including the Mk19 GMG (using 40 mm ammunition), M2HMG (using 12.7 mm ammunition), M240 machine gun (using 7.62 mmammunition), and M249 Squad Automatic Weapon using 12.7 mm ammunition.The GWS can move 360° in azimuth and be mounted in an existing hatchmounting pintle to allow for 360° manual rotation.

Accordingly, in one broad aspect, my invention is directed to a GWS,comprising a weapon cradle, at least one sighting system, an azimuthdrive means for simultaneously moving the sighting system and weaponcradle in azimuth direction, a first elevation means for moving theweapon cradle in elevation, and a second elevation means for moving thesighting system in elevation, the second elevation means capable ofoperating independently of the first elevation means.

Alternatively, my invention is also directed to a gimbaled weaponstation, comprising a weapon cradle, at least one sighting system, anazimuth drive means for simultaneously moving the sighting system andweapon cradle in azimuth direction, a first elevation means for movingthe weapon cradle in elevation, a second elevation means for moving thesighting system in elevation, the second elevation means capable ofoperating independently of the first elevation means, a controlalgorithm means for coordinating movement of the first and secondelevation means, a fire control processor capable of determining a firecontrol solution, and a stabilization system.

In addition, my invention includes a method of maintaining a weapon in acontinuous offset position from a sighting system during operation of aGWS, whereby the sighting system is elevated using an elevationmechanism to acquire a target based on signals received from anobservation unit located remotely from the GWS. An observation unit canbe a combination of the operator interface and display, for example onethat is located in the crew compartment remote from the actual weaponcradle and sighting system. Alternatively, an observation unit maycomprise one or more target sensors that can detect a probable targetwithout human observation, for example by using acoustic sensors, radar,infrared detection, or a combination of these sensors, or any other typeof sensor known to the art. The target sensors could be portable andpositioned locally or remotely from the GWS to monitor and provide awide range of coverage. In addition, target determination may beaccomplished using a network of sensors. These sensors may be hosted bysatellites, manned aircraft, unmanned air vehicles (UAV), groundvehicles, and may include other GWS systems, remote human observation,or a combination of such sensor systems, where the coordinates orlocation of the target is sent to the GWS control unit over a wired orwireless network, such as the Internet, an intranet, or WiFi. Uponreceipt of the target information from the sensors, the GWS is cued andthe sighting system commanded to point at the target location orcoordinates for observation in preparation for target engagementAlternatively, the target sensors, after detecting a probable target,would interface with the control unit of the GWS, typically bytransmitting electrical signals or radio waves. The control unit wouldthen begin tracking the target automatically by controlling the azimuthand elevation means, compute a fire control solution and engage thetarget, all without human intervention. Alternatively, the control unitcould activate an alarm to notify the GWS operator of a probable target.Upon receiving indication of a probable target the operator could takeactive control of the sighting system using the operator interface totrack, range and engage the target. It desirable to have the controlunit automatically adjust the azimuth and elevation of the sightingsystem so that when the operator is notified of a probable target thesighting system will be positioned to observe the target when theoperator consults the display. Likewise, it is desirable to have theweapon cradle also moved to a predetermined aim point based on theprobable target's location. The elevation of the sighting system isdetermined or sensed using a first position sensor that is incommunication with the control unit. The position of the weapon cradleis determined using a second position sensor, which is likewise incommunication with the control unit. The control unit calculates apredetermined offset elevation for the weapon cradle based on theelevation of the sighting system. The elevation of the weapon cradle andinstalled weapon is changed using a completely different and independentelevation mechanism to achieve the predetermined offset elevationcalculated by the control unit. These steps are repeated for each newelevation of the sighting system.

In some tactical situations during target observation it is desirablenot to have the mounted weapon pointed at or near the target, forexample, in crowd control situations a pointed weapon may cause panic orinsight undesirable behavior. Accordingly, my invention may contain anoptional feature whereby the operator or the commander can execute analgorithm in the control unit whereby the gun mount does not track withthe sighting system. Preferably, this algorithm upon execution willplace the weapon cradle and mounted weapon in a non-hostile position,for example in a stowed position or a position where the weapon's bore,or aimpoint, is not in a line of sight with a target being observed bythe sighting system.

My invention may also include a means to record target engagement,whether that engagement is merely observation by the sighting system orby both the sighting system and actual weapon fire. In either case, therecording means will allow playback of the target engagement at a futuretime for evaluation and analysis. The image received and observed by thesighting system, including both visual and thermal, is recorded by anynumber of available and well-known recording systems and media. In onepossible embodiment a continuous loop of recording provides a foolproofmeans to capture a particular target engagement action.

Another optional feature of my invention is commander override. Thisallows the commander of the GWS weapon or its location, or other personhaving authority, over the GWS to execute an algorithm in the controlunit that prevents the operator of the GWS from firing the mountedweapon. A preferred commander override system includes a separateobservation unit or commander monitor that allows the commander toobserve the same images being observed by the operator. If the commandermakes a decision not to engage a particular target being observed, he orshe can execute an algorithm that disables the operator's ability tofire upon the observed target. Along the lines of the commander overridefeature is the establishment or creation of no fire zones by either theoperator or the commander. A no fire zone is a predetermined set ofcoordinates, typically in azimuth, whereby weapon fire is purposelydisabled for a period of time corresponding to the predetermined no firezone. For example, during observation using the sighting system theoperator can select a beginning or starting point of the no fire zoneand the azimuth coordinates for the beginning of the zone are stored inthe control unit memory using a no fire zone algorithm. The sightingsystem is further used to select or determine the coordinates for theend point of the no fire zone, which are likewise retained in memory bythe control unit. Multiple no fire zones can be placed into memory. Whenthe no fire zone option is engaged, traversing or slewing the GWS inazimuth between the starting and ending coordinates of the no fire zonethe control unit will prevent weapon fire in that predetermined zone orzones. This option finds utility in situations where certain structures,such as equipment (i.e., an antenna, hatch, etc.) or historicalbuilding, happens to be within the LOS of sighting system and as suchcould receive weapon fire whether intentionally targeted or not. Oncethe GWS is slewed out of the no fire zone the control unit will againallow weapon firing.

Another method of my invention relates to positioning a weapon duringoperation of a GWS based on target acquisition obtained from a sightingsystem where the sighting system is elevated with an elevation mechanismto acquire a target based on signals received from an operator interfaceand display, or from one or more target sensors located remotely fromthe GWS. A target distance is determined using a range location deviceand the elevation of the weapon cradle is determined with a firstposition sensor. Next a fire control solution is calculated using alogic algorithm that receives as input at least the distance to targetand the elevation of the weapon cradle. After the fire control solutionis calculated the elevation of the weapon cradle and installed weapon ischanged without changing the elevation of the sighting system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram representing the GWS of myinvention.

FIG. 2 is a schematic block diagram of elevation control system forcoordinating the elevation axes of the weapon cradle and sightingdevice.

FIG. 3 is a detailed algorithm of the elevation control system of myinvention.

FIG. 4 is a perspective view of one embodiment of the GWS of myinvention.

FIG. 5 is a perspective view of another embodiment of the GWS of myinvention.

FIG. 6 is a top view of the GWS of my invention showing the sightingsystem in connection with a second azimuth drive means.

FIG. 7 is a side view of the GWS of my invention showing the LOSreflector and sighting device in connection with a second azimuth drivemeans.

DESCRIPTION OF PREFERRED EMBODIMENTS

My invention is directed to a self-contained gimbaled weapon system(GWS) that has a sighting system and a weapon cradle where each has itsown independent elevation axis. The GWS moves 360° in azimuth and allowsthe sighting system and weapon cradle to each move in elevationindependently of each other, thereby allowing a weapon operator toalways maintain visual contact with a target through the sightingsystem, yet allows the weapon cradle to achieve super-elevationpositions to accommodate correct ballistic trajectories. FIG. 1 is ablock diagram of my invention showing GWS 10 comprising sighting device1 connected to a first sighting elevation means 3, which is detachablyconnected to azimuth drive means 5. Weapon cradle 2 is connected to asecond elevation means 4, which, like first elevation means 3, isconnected to azimuth drive means 5. Control of both elevation means 3and 4 and azimuth drive means 5 is accomplished with control unit 6.Control unit 6 is connected to operator interface 7 and display 8,preferably with the interface and display located remotely from thecontrol unit, azimuth drive means, the weapon cradle, sighting device,and the two elevation means. GWS command and control data can be enteredthrough the operator interface 7 and display 8. In situations where theGWS is used on a vehicle platform, display 8 and interface 7 are locatedwithin the interior of the vehicle and all other components are locatedexternally, preferably mounted to the roof of the vehicle.

Operator interface 7 is preferably any interface that an operator canuse to provide control of the azimuth drive means and the sightingsystem elevation means, including an “X-box” type controller or joystick device. Either is designed such that its operation is similar towhat a user of a typical video game would experience. Display 8 receivesinformation from control unit 6, such as video images, ranging data,weapon identification, ambient conditions, and other information neededby the weapon operator to acquire, track and fire on a target. Thedisplay is preferably a night and daylight readable active matrix liquidcrystal display (LCD) having 800×600 pixels and is SVGA and RS-170(NTSC)/CCIR (PAL) compatible. The display can also have an embedded textand graphic processor and can be fitted with a hood to further enhancethe operator's view of the screen when exposed to bright sun light. Thedisplay also can provide a white and black reticle simultaneously, whichis automatically viewable in all light conditions and allcontrast/brightness levels of the display. Optionally, GWS can include asecond observation unit having its own a separate display for thevehicle commander or other entity having operational control over theoperation and firing of the GWS. This separate display is sometimesreferred to as a commander monitor. This second observation unit can bein communication with the first observation unit or directly with thecontrol unit or with both. Regardless of the communication connection,the second observation is capable of accepting instructions from theuser to override a fire command from the first observation unit. Such asituation would occur if the commander or other authorized entity makesa decision that the target being observed by the first observationshould not be fired upon or not continue to be engaged by the weaponmounted on the GWS.

Once a target is identified, a laser range finder as previouslydiscussed and which is part of sighting device 1, is used to determinerange to target. Alternatively, the weapon operator can manually inputthe range to target through interface 7 or display 8. This externalrange data can be determined directly by the operator or received fromother external sources, for example, via radio communication orelectronically from another GWS or similar weapons system. Azimuth drivemeans 5 rotates the entire GWS system giving the weapon operator a 360°field of view. The design of the azimuth drive means is not critical tomy invention and any mechanism known to the art can be used.

Elevation means 3 and 4 are separate mechanical actuators comprising anyknown system of devices that can increase or decrease the elevation ofsighting device 1 and weapon cradle 2. For example, the elevation meansmay comprise a motor and gear system or a direct motor drive system. Apreferred elevation means is a motor and gear system, with the mostpreferred being a harmonic drive coupled to a servo motor. Likewise, itis within the scope of my invention that the elevation means could use afluid driven actuator such as a hydraulic cylinder. Regardless of thespecific system that is chosen, the elevation means should be capable ofmoving the weapon cradle and sighting system quickly and smoothly inresponse to operator commands. Most importantly, elevation means 3 mustbe a completely independent system from elevation means 4, thus allowingthe weapon cradle to be elevated to a super-elevation position withoutaffecting the elevation of sighting device 1. Likewise, sighting device1 can be elevated without changing the elevation of weapon cradle 2.Position sensors (not shown) determine the elevation position of theweapon cradle and sighting device. Any type of position sensor known tothe art will work with my invention. These position sensors provideelevation position information to the control unit, which in turn usesthe information, along with other inputs, to compute a fire controlsolution.

The GWS of my invention can also contain a stabilization system orsystems. Preferably, the GWS would contain at a minimum a stabilizationsystem on the azimuth axis. Most preferably the GWS would also includesight elevation stabilization and/or weapon cradle elevationstabilization. Any type of known stabilization system can be used withmy invention; however, a preferred stabilization system is one that usesfiber optic gyros. In the direct inertial rate stabilized approach thegyros move with the mechanical system to stabilize and a servo loop isused to regulate a null rate. Alternatively, the gyros can be mountedoff-axis, where the gyros sense base motion and an elevation loop iscommanded equal and opposite to the sensed based motion. When used on amoving vehicle and aiming at a stationary target, the GWS should provideweapon and sighting system stabilization sufficient to allow a gunner,moving over cross-country terrain to achieve at least one hit from aburst of fire against a vehicle-like stationary target located about 500meters distant. This would apply to moving toward or away from a target.Likewise, when the target is moving it is preferred that the GWS canprovide weapon and sighting system stabilization sufficient to allow agunner in a vehicle, moving over cross-country terrain, less than about3 mils, visual contact with a vehicle sized target up to about 1500meters distant moving in the opposite direction over cross-countryterrain.

Power to drive the azimuth and elevation drive means is supplied by anexternal source and is not part of the GWS. For example, when the GWS ismounted to a vehicle, the GWS will use the host vehicle's power system.Control unit 6 contains a fire control processor which calculates anddetermines fire control solutions based on target range data, ambienttemperature and air pressure, weapon type, ammunition type, platformcant and bore sight information. Control unit 6 also contains software,which executes a control algorithm that coordinates movement of theweapon cradle elevation means and sighting device elevation means. Thecontrol unit contains industry standard computer architecture with astate-of-the-art central processing unit (CPU). This computerarchitecture supports target tracking, coordination of the two elevationaxes, fire control and other advanced sighting features including aninfrared thermal imaging device, a visible imaging device, and a laserrange finder. As schematically shown in FIG. 2 this control algorithmreceives input from the fire control processor, weapon operator,inertial sensors, and relative position sensors located on the weaponcradle and sighting system. Using these inputs, the control algorithmcauses the elevation means associated with the sighting system andweapon cradle axis to reposition as needed for accurate weapon firing.

FIG. 3 presents a further description of the elevation control algorithmindicating three modes of operation of the GWS; surveillance mode, firecontrol solution and tracking. Many possible control protocols can bepredetermined and programmed into the central processor unit containedin the control unit. For example, in any of the three modes, the weaponcradle can remain stationary in elevation with the sighting system freeto move in elevation while the operator acquires and tracks a target.Once a fire control solution has been determined by the fire controlprocessor, the weapon cradle (and attached weapon) would be moved by itsassociated elevation means to the proper elevation needed to ensure theprojectile hits the designated target. Alternatively, the controlalgorithm could cause the weapon cradle to continuously move inelevation in response to movement of the sighting system without firstreceiving input from the fire control processor. In this controlprotocol, the control algorithm would move the weapon cradle to apredetermined estimated offset elevation anticipating a finalsuper-elevation position that will ultimately to be determined by thefire control processor. By continuously having the weapon cradle alreadyoffset by a predetermined estimated amount will result in less elevationdistance travel for the weapon cradle once a final fire control solutionis determined. In addition, this predetermined offset scheme will leadto a faster fire control solution.

FIG. 4 illustrates one embodiment of the GWS of my invention where theoperator interface and display (both not shown) are located remotely.GWS 20 has azimuth drive means 25 positioned over platform mountingplate 27. Weapon cradle elevation means 22 is connected to weapon cradle23 which is designed to accommodate a number of standard military issuedweapons, including machine guns and grenade launchers, without requiringmodification to the weapon. As mentioned, GWS 20 can also include asmart system which will detect the type of weapon mounted on weaponcradle 23 and will provide that information to control unit 26, which inturn uses that information to determine fire control solutions andprovides feedback to the weapon operator. Optical sighting device 24 ismoved in elevation by elevation means 21 independent of weapon cradleelevation means 22. Sighting device 24 can include a thermal imagingdevice and or a daylight imaging device to provide video for a real timeon-screen display (not shown), both of which can be operated remotelyfrom a user interface (not shown), such as with a joystick. The abilityto magnify the video image is also desirable, with a preferredmagnification in the range of about 0.5× through 8×. The video imagingdevices could also be used to perform target tracking, which can be usedto accurately determine a fire control solution. Also included on thesighting device would be a range determination means, preferably anactive device, such as a laser range finder. Likewise, a passive devicecould also be used. The sighting device may also contain an acousticdevice for target detection and/or a motion sensor to alert the operatorof contact with a possible moving target.

To allow for remote operation of the weapon cradle and sighting devicethe connection of control unit 26 to an operator interface and displayis preferably accomplished with a single through-hull, quick-disconnectelectrical connector. The quick-disconnect is preferred in situationswhen power loss may occur and manual operation of the GWS is thenrequired. The GWS of my invention also allows for aligning theline-of-sight (LOS) of sighting device 24 with the bore of whateverweapon is mounted on the GWS. Both manual and electronic bore sightingis possible and follows well known and established protocols. FIG. 5shows another embodiment of my invention with weapon 110 mounted incradle 23, and sighting device 24 reoriented.

The display/monitor used by the weapon operator can be a night anddaylight readable active matrix liquid crystal display (LCD), eithercolor or black and white. The display can also function as an operatorcommand and control interface by providing a touch sensitive screen. Itis preferred that the display and operator interface be located remotelyfrom the sighting system and weapon cradle combination. In situationswhere the GWS is used on a moving vehicle, the display and operatorinterface are preferably located in the vehicle crew compartment. Inaddition to viewing the video output from the sighting device, thedisplay also can include operator messages, target reticle and line ofsight indication determined and generated by the control unit. Operatormessages could include the identification of the weapon in the weaponcradle, GWS mode of operation (i.e., safe, fire, tracking, etc.),azimuth and elevation indication of the weapon, and ammunition type. Asmentioned, my invention may also contain a second azimuth drive means inaddition to the azimuth drive means which moves the entire GWS, i.e.,gun mount and sighting system. A smaller, secondary azimuth drive meansis necessary to keep the sighting system in LOS with the target in thosesituations where the control unit calculates a fire control situationthat requires target lead, wind correction or other azimuth deviationfrom the LOS of the target. FIG. 6 shows one possible embodiment of myinvention in a block sketch of the GWS view from above. Weapon cradle 23is attached to the main body of 106 of the GWS Drive means 22independently elevates weapon cradle 23 from drive means 21, which isused to elevate sighting system 107. A secondary azimuth drive means 102is shown connected to the sighting system and allows the sighting systemto move in an arcuate azimuth direction 103 about arcuate track 104. Aworm gear or other drive mechanism is part of drive means 102 thatallows track 104 to move in direction 103 about track 101 and oppositeto direction 105 of primary azimuth drive means 25. Because secondaryazimuth means 102 is connected to elevation means 21, the sightingsystem 107 and secondary azimuth means 102 can be elevated by drivemeans 21 independent of drive means 22. FIG. 6 shows the sighting system107 comprising just the sighting device 24 as described above, however,a preferred alternate embodiment (see FIG. 7) includes sighting system107 comprises sighting device 24 in combination with a LOS reflector200, where LOS 200 reflector is mounted to secondary azimuth means 102in place of sighting device 24. In such an embodiment sighting device 24would be mounted in a fixed position on main body 106 where is wouldreceive a reflected image of the target 210 from LOS reflector 200. Thisalternative allows sighting device 24 to be mounted in a fixed positionand protected from damage or obstructed view due to environmentalconditions (rain, dust, snow, etc.) or from enemy fire. In addition,because the sighting device 24 is much heavier than an LOS reflector,which in its basic form is a glass mirror or other optically reflectivesurface, the secondary drive means 102 and elevation means 21 aresubjected to less stress, wear and tear, and both can be of a lessmassive design than needed to move sighting device 24. A variety ofdifferent designs exist for achieving the purposes of the LOS reflectorof my invention, including designs disclosed in U.S. Pat. No. 6,123,006,which is incorporated herein by reference. Although the specific detailsof the LOS reflector are not critical to my invention, it is necessarythat sighting device 24 is mounted to main body 106 such that a targetimage captured and reflected by the LOS reflector will be observed bythe image detector contained in sighting device 24. Regardless of thedesign selected for the LOS reflector it is necessary that the LOSreflector itself or the control unit contain the appropriate devices orsoftware to ensure that the image observed on the observation units isan accurate depiction of the actual spatial relationship of the target,i.e. what is observed as “right” is “right” and what is “up” is “up”.

While my invention has been described in it preferred embodiments, it isto be understood that the words which have been used are words ofdescription, rather than limitation, and that changes may be made withinthe preview of the appended claims without departing from the true scopeand spirit of the invention in its broader aspects.

1. A method of bore sighting a weapon mounted to a gimbaled weaponsystem (GWS), comprising the following steps, in combination: a)providing a GWS having a sighting system, a weapon cradle, a weaponhaving a defined bore, and a sensor aligned with the bore of the weapon,the sighting system receiving signals from an observation unit locatedremotely from the GWS; b) observing a target image produced by a sensoraligned with the bore of the weapon at the observation unit; c)observing a target reticle produced by the sighting system at theobservation unit; and d) bore sighting the weapon by adjusting thetarget reticle such that it is in alignment with the target image. 2.The method of claim 1, wherein the steps b, c, and d are performed for aplurality of different ranges.
 3. A method of bore sighting a weaponmounted to a gimbaled weapon system (GWS), comprising the followingsteps, in combination: a) providing a GWS having a sighting system, aweapon cradle, a weapon having a defined bore, and a sensor aligned withthe bore of the weapon, the sighting system receiving signals from anobservation unit located remotely from the GWS; b) observing a firsttarget image produced by the sensor aligned with the bore of the weaponat the observation unit; c) observing a second target image produced bythe sighting system at the observation unit; and d) bore sighting theweapon by adjusting the second target image such that it is in alignmentwith the first target image.
 4. The method of claim 3, wherein the stepsb, c, and d are performed for a plurality of different ranges.